Vacuum Ultraviolet Negative Photoion Spectroscopy of SF5Cl

Abstract

____________________________________________________________Using vacuum-UV radiation from a synchrotron, gas-phase negative ions are detected by mass spectrometry following photoexcitation of SF 5 Cl. Cl − signal is much weaker, despite the S−Cl bond being significantly weaker than the S−F bond.Appearance energies for F − and Cl − of 12.7 ± 0.2 and 10.6 ± 0.2 eV are determined. The spectra suggest that these ions form indirectly by crossing of Rydberg states of SF 5 Cl onto an ion-pair continuum.